Central Limit

Gist

Considered the most fundamental theory in modern statistics.

Definition

If you a sample of random variables and average it. Do it multiple times. It should look like a Normal Distribution. This is important because we can then use statistical tests that assumes normality even when the underlying data is not normal but the sample size is large enough.

But how much samples?

  1. Roughly symmetric? 15-30
  2. Heavily skewed? 50 or more
  3. Really, really skewed? 100 or more